This is the moment of inertia.

这是转动惯量。

So we know the moment of inertia.

我们得到转动惯量。

What is the moment of inertia of that?

它的转动惯量是多少呢？

You can calculate the moment of inertia.

可以计算其转动惯量。

Well, the moment of inertia is a boring job.

计算转动惯量，是一个枯燥的活。